Self-cleaning valve mechanism



Dec. 14, 1965 PAUL, JR

SELF-CLEANING VALVE MECHANISM Filed Sept. 16, 1963 INVENTOR. 4594/4 .4.#404, we

United States Patent 3,223,173 SELF-CLEANING VALVE MECHANISM Herman L.Paul, In, Wayne, N.Y., assignor to Consolidated Electrodynamics(Jorporation, Pasadena, Calif., a corporation of California Filed Sept.16, 1963, Ser. No. 309,065 4 Claims. (Cl. 169--31) This inventionrelates to valve mechanisms and, more particularly, to self-cleaningvalve mechanisms for p wdertype fire extinguishers and the like.

Powder-type fire extinguishers of conventional manufacture have a shortuseful life because of the valve mechanisms used in such fireextinguishers and because of the granular nature of the materialdischarged through the valve mechanisms. Furthermore, conventionalpowdertype extinguishers are more expensive than necessary to maintainbecause fire inspectors require that each such extinguisher be rechargedafter each use regardless of the extent of the use, not because thecontents of the extinguisher are exhausted, but because the valvemechanism of the device may not be properly closed. Because fireextinguishers must be ready for use on a moments notice, complete safetyrequires that conventional powder-type fire extinguishers be rechargedafter each use.

The valve mechanisms used in conventional powdertype fire extinguisherstheoretically are capable of properly seating themselves so thatrecharging the extinguisher after consumption of only a fraction of thepowder contained therein is unnecessary. In practice, however, thegranular material discharged from the extinguisher fouls the valvemechanism so that the valve does not completely close and the gas chargeof the extinguisher is allowed to be dissipated with the result that theextinguisher is not suitable for use when the next fire emergencyarises. -It is for this reason that conventional extinguishers arerecharged after each use, no matter how slight the use.

This invention provides an improved valve mechanism for use especiallyin powder-type fire extinguishers. The valve mechanism is self-cleaningwith the result that the valve is completely closed when the actuator ofthe mechanism is moved to a position corresponding to closure of themechanism. Moreover, the improved valve mechanism permits convenientmeans for refilling the extinguisher with fire extinguishing materialand for recharging the extinguisher with a gas charge.

Generally speaking, the present invention provides a valve forcontrolling the discharge under pressure of flowable material from acontainer having a quantity of gas therein under pressure for chargingthe container. The valve comprises a housing defining a passagetherethrough, one end of the passage communicating with the material inthe container. First and second check valves are dis posed in thepassage. Means are provided for supplying a gas under pressure from thecontainer to the passage at a point intermediate the valves. The secondvalve is located more remote from the one end of the passage than thefirst valve. Selectively operable means are provided and are operablefor forcing open the valves against pressure biasing them closed. Theselectively operable means includes means for opening the first valveonly when the second valve has opened a predetermined amount.

The above-mentioned and other features of the present invention are morefully set forth in the following detailed description taken inconjunction with the accompanying drawing which is a cross-sectionalelevation view of a fire extinguisher equipped with an improve valvemechanism.

The drawing illustrates a fire extinguisher which is comprised of acontainer 11 and a discharge valve mechanism 12. The container includesa cylindrical collar 13 extending upwardly from the upper end of thecontainer and disposed about an aperture 14. The collar is threaded3,223,173 Patented Dec. 14, 1965 internally for engagement with anexternally threaded sleeve 15 having an axial bore 17 therethrough. Thelower end of sleeve 15 is connected to the upper end of a hollow tube 18which extends downwardly through the interior of the container toterminate at a location spaced from the bottom of the container in abody of powdered fire extinguishing material 19 disposed in the lowerportion of the container. A void space 20 is formed in the containerabove the powder; this space is filled with pressurized charging gas.

The upper end of sleeve 15 is connected to a valve block 22 which has abore 23 formed therethrough. The combination of block 22, sleeve 15 andnozzle 40 (described below in greater detail) defines a valve housing.B-ores 17 and 23 are coaxial with one another when the sleeve isconnected to the block and, in combination with nozzle discharge duct41, define a passageway through the valve housing. The upper end of bore23 opposite from sleeve 15 is closed by a plug 24 which has formedtherethrough a small diameter bore 25 aligned coaxially of bore 23. Aplunger-type actuation member 26 is slidably mounted in plug bore 25 andis sealed in g-astight relation to the plug by means of an O-ring 27; itis within the scope of this invention, however, that any conventionalgasketing material may -be used to seal the plunger to the plug.Internally of the valve housing passageway, the plunger defines anenlarged head 28 which is configured to cooperate with the lower end ofthe plug to limit the upward movement of the actuator relative to valvehousing. The plunger is biased upwardly from the valve housing by aspring 29 disposed about the plunger between plug 24 and an enlargedupper head 51 of the plunger.

The upper end of sleeve 15 defines an externally threaded nipple 30which is engaged with an internally threaded, enlarged diameter lowerportion of bore 23. Bore 17 is enlarged in the vicinity of the nipple(as shown at 31) to receive a first valve member provided in the form ofa ball 32 which preferably has a diameter smaller than the diameter ofbore 17. An O-ring 33, for example, is engaged in a recess formedannularly of bore 17 below the nipple. The O-ring is provided forretaining ball 32 in the vicinity of the nipple so that it does not passthrough the sleeve into tube 18.

A first valve seat 34 is provided transversely of the valve housingpassageway and is defined by an annular washer 35 disposed between theupper end of nipple 30 and a downwardly opening shoulder formed in thevalve block at the upper end of the enlarged diameter lower portion ofbore 23. As seen from below, i.e., from the direction of ball 32, thewalls of the opening in washer 35 which define the valve seat arespherically concave so that the ball may mate intimately with the seat.

A powder discharge nozzle 40 is connected to the valve block above thefirst valve seat and defines a nozzle discharge duct 41 which extendsthrough the nozzle block and communicates with bore 23 above ball 32. Asshown in the drawing, the nozzle discharge duct increases in diameterproceeding away from bore 23. The intersection of the nozzle duct withbore 23 defines a second valve seat 43. A second valve member in the.form of a ball 44 is disposed in bore 23 above the first valve seat andis engageable in closure relation with seat 43. When ball 44 is engagedwith its seat, a slight clearance is provided between the ball and thelower end of valve actuator 26.

A by-pass gas duct 46 communicates with bore 23 on the side of ball 44opposite from seat 43. Preferably, as shown in the drawing, duct 46 iscoaxial with discharge duct 41, although such need not be the case forsuccessful practice of this invention. A length of small diameter tubing47 has one end thereof connected in fluid flow communication with gasduct 46 by means of a fitting 48.

The other end of tubing 47 is connected in fluid flow com-' municationwith the gas charge contained in space 24} in the upper end of fireextinguisher container 11.

In considering the operation of the apparatus described above, let it beassumed that the fire extinguisher is properly filled with powder 19 andis suitably charged with a quantity of charging gas. Assume also thatthe valve mechanism is in the unactuated condition shown in the drawing.Ball 44 is then engaged in closure relation with seat 43 and is held insuch relation by means of the pressure drop existing across the ball,the pres-sure of the gas charge in the fire extinguisher beingsubstantially greater than atmospheric pressure. When ball 44 is seatedas shown in the drawing, there will be no gas flow through tubing 47 andball 32 may be disengaged from closure relation with its valve seatbecause the gas pressure in bore 23 is equal to the pressure in tube 18.

The valve mechanism is operated by depressing actuator plunger 26 sothat actuator head 28 engages ball 44 and moves the ball out of closurerelation with seat 43. A small quantity of charging gas will thencommence to flow through duct 47, but since the duct has a very smalldiameter there is a substantial head loss as the gas flows through theduct. To assure the desired head loss, fitting 48 defines an orifice 49in the by-pass duct, but the orifice may be omitted where tube 47 itselfprovides the desired pressure drop. Charging gas, however, is caused toflow transversely of bore 23 with a velocity sufficient to manifest aneductor effect to raise ball 32 into engagement with its seat 35.Continued depression of the actuator, however, quickly brings ball 44into engagement with ball 32 and disengages ball 32 from closurerelation with its seat so that the valve passageway is completelyopened. When the valve is operated according to the process describedabove, the resistance to gas flow through tube 18 is substantially lessthan the gas flow resistance through tubing 47 and, therefore, thecharging gas in the upper end of the container forces powder 19 upwardlythrough the tube and out of the fire extinguisher through discharge duct41. The powder contained in the lower portion ofthe fire extinguisher isfinely divided so that it is readily flowable through the valvemechanism in the escaping stream of charging gas.

To close the valve mechanism completely, it is only necessary for theoperator of the fire extinguisher to remove his finger from the upperend of actuator 26 so that spring 29 is effective to return the actuatorto the position shown in the drawing. As the actuator returns to itsunoperated position, the gas flowing out of the fire extinguisherthrough the valve housing passageway causes ball 32 to engage with itsseat. Charging gas continues to flow, however, through tubing 47 andforces ball 44 into closure relation with seat 43. As the ball movesinto engagement with its seat, the small quantity of charglng gasescaping from the fire extinguisher washes the ball of all particles ofpowder which may adhere thereto. Seat 43 is also cleansed of residualpowder particles. As a result, the engagement of ball 44 with seat 43 iscomplete and the valve mechanism is securely closed so that no charginggas can escape from the fire extinguisher. The upper ball is thereaftermaintained across dlscharge duct 41 by reason of the pressure dropexisting across the ball.

The apparatus described above has the feature that the valve member andvalve seat which cooperate to effect terminal closure of the mechanismare automatically cleansed by the operative fluid of the extinguisher.Accordingly, the fire extinguisher is completely sealed and there is nochance that the gas charged in the extingulsher may leak between uses ofthe device. It is therefore pot necessary for the extinguisher to beserviced after a use in which only a fraction of the powder enclosed incontainer 11 is discharged.

The apparatus described above also has the feature that it provides forconvenient recharging and refilling of the extinguisher. Tubing fitting48 may be disengaged from block 22 and the entire valve mechanismincluding tube 18 may be disconnected from the container by means of thethreaded connection between collar 18 and sleeve 15. After a quantity ofpowder 19 is introduced into the container, the valve mechanism isreplaced and fitting 48 is reconnected to the mechanism. A quantity ofcharging gas is then injected into the container merely by coupling asuitable fitting to the nozzle of the fire extinguisher through whichcharging gas may be introduced into space 29 at the upper end of thefire extinguisher container. The charging gas is inserted into thecontainer by way of tubing 47 as well as through the valve housingpassageway.

The foregoing description is made with reference to the discharge of afinely divided powder through the valve mechanism. It will be apparentto those skilled in the art that the improved valve mechanism may beused to regulate the discharge of liquids, and that the invention hasutility in devices other than fire exting ishers.

While the invention has been described above in conjunction withspecific apparatus, this has been by way of example only and is not tobe considered as limiting the scope of this invention.

What is claimed is:

1. A valve for controlling the discharge under pressure of flowablematerial from a container having a quantity of gas therein underpressure for charging the container, the valve comprising: a housingdefining a passage therethrough, the housing being adapted forconnection to the container so that one end of the passage communicateswith the interior of the container; firs-t and second valve seatspositioned across the passage at spaced apart locations along thepassage; first and second movable valve membens disposed in the passageengageable in closure relation with the first and second valve seats,respectively; the valve members being disposed toward said one end ofthe passage from their respective seats, the second valve member beingmore remote from said one end of the passage than the first valvemember; selectively operable means operable in one direction for movingthe first and second valve members fro-m closure relation with theirseats and operable in a reverse direction to engage first the firstvalve member and then the second valve member with their respectiveseats; and charging gas duct means communicating with the passageadjacent the second valve seat and adapted remotely from the passage forgas fiow communication with the interior of the container.

2. A valve for controlling the discharge under pressure of material froma container having a quantity of gas under pressure therein for chargingthe container, the valve comprising a valve housing adapted forconnection to the container and defining an internal valve chamber, tubemeans communicating with the chamber and extending from the valvehousing for directing flow of the material therethrough to the valvechamber, a first valve seat positioned across the valve chamber, amovable first valve member disposed in the valve chamber between thetube means and the first seat and engageable in closure relation withthe seat, and valve housing defining a discharge duct intersecting thevalve chamber adjacent the side of the first valve member opposite fromthe tube means and defining a second valve seat about the intersectionof the discharge duct with the valve chamber, a movable second valvemember disposed in the valve chamber and engageable in closure relationwith the second valve seat, selectively operable means for moving thesecond valve member and the first valve member sequentially from closurerelation with their respective seats upon operation thereof, and gasduct means communicating with the valve chamber adjacent the secondvalve member and adapted for connection remotely from the valve chamberwith the container for flow of said charging gas therethrough.

3. A valve for a pressure charged container adapted for containing aquantity of dispensible material in a lower portion thereof and agaseous pressure charge in an upper portion thereof, the valvecomprising a valve housing connected to the container and defining avalve chamber internally thereof, tube means communicating the valvechamber with the container lower portion, the valve housing defining afirst annular valve seat across the valve chamber, a first valve balldisposed in the valve chamber between the tube means and the first seatand engageable with the seat, the valve housing defining a dischargeduct intersecting the valve chamber opposite the first seat from thetube means, a second annular valve seat disposed about the intersectionof the discharge duct with the valve chamber, a second valve balldisposed in the valve chamber engageable with the second valve seat,selectively operable means for moving first the second valve ball andthen the first valve ball from engagement with their respective seatsupon operation thereof, and gas duct means communicating from the upperportion of the container to the valve chamber opposite the second valveseat.

4. A valve for a pressure charged container, the container containing aquantity of dispensible material in a lower portion thereof and agaseous pressure charge in an upper portion thereof in communicationwith the dispensible material, the valve comprising a valve housingconnected to the upper end of the container and defining -a verticallydisposed internal valve chamber, means communicating the chamber withthe container lower portion for flow of the dispensible materialtherethrough to the valve chamber, the valve housing defining a firstannular valve seat intermediate the vertical extent of the valvechamber, a first valve ball disposed in the valve chamber below thefirst seat and engageable with the seat, means carried by the valvehousing for maintaining the first valve ball in the vicinity of thefirst seat, the valve housing defining a discharge duct transverselyintersecting the valve chamber above the first seat and defining asecond annular valve seat at the intersection of the discharge duct withthe valve chamber, a second valve ball disposed in the valve chamberengageable with the second valve seat, selectively operable means formoving first the second valve ball from the second valve seat and thenthe first valve ball from the first valve seat upon operation thereof,andgas duct means communicating from the upper portion of the containerto the valve chamber opposite the second valve seat.

References Cited by the Examiner UNITED STATES PATENTS 1,197,832 9/1916La May 16931 2,513,377 7/1950 Stroop. 2,717,804 9/1955 White 239353 XFOREIGN PATENTS 1,040,155 5/1953 France.

916,495 8/ 1954 Germany.

EVERETT W. KIRBY, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,223,173 December 14, 1965 Herman L. Paul, Jr.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 1, line 67, for "improve" read improved column 2, line 21, after"plunger-type" insert valve column 4, line 59, for "and" read the Signedand sealed this 27th day of September 1966.

(SEAL) Attest: ERNEST W. SWIDER EDWARD J. BRENNER Attesting OfficerCommissioner of Patents

